Hand held electronic devices, portable electronic devices, wireless communication devices and the like need to operate using a portable energy source, such as a rechargeable battery. Many efforts are made in the design of these devices, their circuitry and their modes of operation in order to lower their power consumption as much as possible without substantially affecting their performance. One of the parameters by which power consumption of such devices may be affected is the control of the supply voltage to the active units in the electronic circuitry. The lower the supply voltage, the lower the consumed power.
For certain needs two different levels of supply voltage to an electronic circuit may be defined. The first is the minimum level of power supply voltage which may still guarantee that the logical levels at the various pins of units in the circuit are retained. This voltage level is sometimes called stand-by VccMin. The other level is the minimum level of power supply voltage at which the associated unit may still operate. This voltage is sometimes called active VccMin. Active VccMin may further have two different typical values. The first is defined as the lowest voltage at which lowering of the frequency will no longer enable to write to a memory cell in the register file. This value is sometimes defined as DC Write VccMin. The other value of active VccMin is the lowest voltage value which still allows completion of ‘write’ operation to a memory cell in register file for a given frequency. This voltage value is sometimes called AC Write VccMin. The actual level of any of these voltage levels may be affected by several factors, comprising the functionality of the unit, the technology of the unit, the scale and density of the unit, the frequency of operation of the unit, the pulse width at given lines and pins, etc.
One type of electronic unit that may be affected by at least the pulse width is the register file, which is, generally speaking, an array of storage registers that may have more than one set of ports for Read/Write operations, thus allowing more than one source/destination of data to cooperate with the register file.
It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.